“It's an absolute blessing that they weren't hurt worse,” said Michael Lemon, a trauma medical director at Eastern Idaho Regional Medical Center.
He was speaking after a girl opened fire at a school in the north-western US state of Idaho on Thursday, injuring three people before being disarmed by a teacher, police said.
The unnamed student at Rigby Middle School near Idaho Falls was in the sixth grade, meaning she would likely be aged 11 or 12.
She “retrieved a handgun from her backpack, fired multiple rounds inside of the school and out”, said Jefferson County sheriff Steve Anderson.
Injuries suffered by two students and one staff member are not thought to be life-threatening, he said.
“During the shooting a teacher disarmed the student, and detained her until law enforcement took her into custody,” added Anderson at a press conference.
The wounded adult was treated and released for a bullet wound that went through an extremity.
Authorities said they were investigating the motive for the attack and where the girl got the gun
“We don't have a lot of details at this time of ‘why' — that is being investigated,” Jefferson County Sheriff Steve Anderson said.
Police were called to the school around 9.15am after students and staffers heard gunfire. Multiple law enforcement agencies responded, and students were evacuated to a nearby high school to be reunited with their parents.
“Today we had the worst nightmare a school district could encounter,” the Jefferson school district superintendent, Chad Martin, said later in the day.
Martin said schools would be closed district-wide to give students time to be with families, but that counsellors would be available starting on Friday morning.
Rigby middle school has about 1 500 students, according to the National Center for Education Statistics.
The shooting is being investigated by the FBI as well as local law enforcement.
The US has suffered a spate of mass shootings in recent weeks, including at a FedEx facility in Indianapolis, an office building in California, a grocery store in Colorado and at several spas in Atlanta.
President Joe Biden last month branded US gun violence an “epidemic” and an “international embarrassment”
There were more than 43 000 gun-related deaths in the United States last year, including suicides, according to the Gun Violence Archive.